Organisms responding under intermittent reinforcement schedules have been found to engage in a variety of adjunctive or schedule-induced activities, usually just following the delivery of food. Among these behaviors are polydipsia, attack, escape, wheel running, and pica. In the present study, pigeons will be trained to respond under fixed-interval food schedules. Concurrently available to the pigeons will be a stuffed target for recording attacks and a second operandum for initiating escapes or stimulus change. The levels of attack and escape behaviors generated will then be assessed over a range of schedule values under each of three conditions: target alone available, escape alone available, and attack and escape available concurrently. Completion of these procedures will provide data with implications for each of the following areas: (1) Adjunctive Behavior - provide indices of the relative strengths of attack and escape and aid in the construction of a hierarchy of adjunctive behaviors; studying these activities in a more complex situation may provide new information regarding the causal factors in their generation; (2) Control of Aggression - provide information on the effectiveness of alternative response availability in reducing or eliminating schedule-induced aggression. Such information will provide groundwork for future investigation into the necessary conditions for human and animal aggression; (3) Drug Effects - provide for the refinement of a new technique for establishing a sensitive baseline against which drug-related behavioral effects can be measured.